When this research was performed, the authors were with the Department of Electronic Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.

R. Thapliya is now with the Optical System Technology Development Unit, Department of Eco-System Research and Development, Fuji Xerox Company Ltd., New Business Center, 430 Sakai, Nakai-machi, Ashigarakami-gun, Kanagawa 259-0157, Japan.

T. Kamiya (kamiyatk@niad.ac.jp) is now with the National Institution for Academic Degrees, 3-29-1 Otsuka, Bunkyo-ku, Tokyo 112-0012, Japan.

Abstract

The multibeam parallel joint transform correlator for optical
pattern recognition, which was recently proposed by the authors
[Appl. Opt. 37, 5408 (1998)], can increase
parallelism without accumulating zero-order background level at the
first Fourier transform plane. To evaluate the throughput
capability, an experimental trial was made, achieving a 67-ms
recognition rate per face per channel, which is limited by the response
of the optically addressed liquid-crystal spatial light
modulator. A general design theory is developed for dense packing
of the optical channels for a given spatial light modulator resolution,
considering the bandwidth requirement of the target image. Then the
condition for submillisecond throughput with state-of-the-art device
technology is discussed.

Case when there is (a) interdiffraction order overlap
and (b) nonoverlap; (c) fluctuations of normalized outcome
intensity, Om(k′), for k′(=9)
channels when the normalized lens separation, m, changes for
Le/Pe = 0.84 and
Pe = 33 µm. Note the presence
of both destructive and constructive interferences.

a The parameters for the first two devices
are from Ref. 15. The nematic OSLM was taken from
Ref. 16. The SSFLC OSLM was taken from Ref.
17 with pixelated mirrors to increase the reflected
read light. The DHFLC was taken from Ref.
18. The MQW-OSLM was taken from Ref.
19. The SEED parameters are from Ref.
20.

a The parameters for the first two devices
are from Ref. 15. The nematic OSLM was taken from
Ref. 16. The SSFLC OSLM was taken from Ref.
17 with pixelated mirrors to increase the reflected
read light. The DHFLC was taken from Ref.
18. The MQW-OSLM was taken from Ref.
19. The SEED parameters are from Ref.
20.